USPTO Patents Application 09917783

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Claims:

1. A method of centralised data position information storage
comprising the steps of:

arranging a byte stream of data into partitioned logical data;

providing an updateable centralised storage area being operable to store
data position information relating to said logical data;

utilising said information to locate a target data being part of said logical
data; and

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storing said data position information in said storage area.

2. The method as clairned in claim 1 wherein said step of storing said

data position infomnatlon comprises:

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applying a first store algorithm to said target data to update said storage
area with target data position information; and

applying a second store algorithm to non-target data to update said storage
area with non-target data position Information .

3. The method as claimed in claim 2 wherein said first and said
second algorithms are operab!© to store said data position information in a data
table;

wherein said data table is configurable to store data position information
relating to said logical data, said logical data comprising records and filemarks.

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4. The method as claimed in any one of claims 1 or 2 wherein said
step of utilising said data position information comprises:

applying a search algorithm to said data position information;

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wherein said search algorithm is configured to locate said target data.

5. A method of updating data position information on a tape storage
device, said method comprising the steps of:

10

arranging a byte stream of data into partitioned logical data and recording
said data onto a length of tape;

storing data position information relating to said logical data within an
15 updateable centralised storage area;

utilising said information to determine a required transporting of said logical
data passed a read head to allow a target data to be read by said read head, said
target being part of said logical data; and

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updating said storage area with data position information obtained following
a transporting of said logical data passed said read head.

6. The method as claimed in claim 5 wherein the step of updating said
25 storage area comprises:

reading said logical data on said tape using said read head; and

writing said data position information to said storage area;

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wherein said read head is configurable for said reading of said data wl^en a
velocity of transporting said logical data passed said read head is below a pre-
determined value.

5 7. The method as claimed in claim 5 wherein the step of updating said

storage area comprises:

reading said target data on said tape using said read head; and

10 writing target data position Information to said storage area.

8. The method as claimed in claim 5 further comprising the steps of:

transferring said data position information from a reserve storage area to
15 said centralised storage area; and

following said step of updating said centralised storage area, transferring
said data position information from said centralised storage area to said reserve
storage area.

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9. The method as claimed in claim 8 wherein said updateable
centralised storage area contains no data position Information prior to a first
transporting of said logical data passed said read head; and

25 following said first transport:ing of logical data, said data position information

is stored in said centralised storage area.

10. A data position information storage and utilisation device
comprising:

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partitioned logical data distributed across a length of tape;

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an updateable centralised storage area to receive and store data position
information relating to said logical data;

5 a search algorithm to locate a target data being part of said logical data; and

a read head to read said data from said tape;

wherein said information is stored in said storage area foliowing a
10 transporting of said logical data passed said read head.

11. A device as claimed in claim 1 0 further comprising:

a first store algorithm to control the reading of target data from said tape
15 and the storing of said target data position information in said storage area; and

a second store algorithm to control the reading of non-target data from said
tape and the storing of non-target data position information in said storage area.

2 0 12. A device as claimed in claim 10 wherein said updateable

centralised storage area is configurable to store said data position information
relating to substantially all of said logical data.

13. A device as claimed in claim 10 wherein said updateable
25 centralised storage area is configurable to store said data position information

relating to selected data groups, said data groups being distributed across said
length of tape.

14. A device as claimed in claim 11, said device further comprising:

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a tape drive;

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wherein said updateable centralised storage area, said read head, said
search algorithm and said first and said second store algorithms are located in
said tape drive,

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15. A computer program comprising program commands for
implementing a method of centralised data position information storage, said
method comprising the steps of:

10 arranging a byte stream of data into partitioned logical data;

providing an updateable centralised storage area being operable to store
data position information relating to said logical data;

15 utilising said information to locate a target data being part of said logical

data; and

storing said data position information in said storage area.

2 0 16. A computer program comprising program commands for

Implementing a method of updating data position information on a tape storage
device, said method comprising the steps of:

arranging a byte stream of data into partitioned logical data and recording
2 5 said logical data onto a length of tape;

storing data position information relating to said logical data within an
updateable centralised storage area;

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utilising said information to determine a required transporting of said data
passed a read head to allow a target data to be read by said read liead, said
target data being part of said logical data; and

updating said storage area with data position information obtained following
a transporting of said logical data passed said read head.

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